The Stovebolt Site Forums The Shop Area The HiPo Shop Holley Sniper install on a 235

Just finished the install of a Holley Sniper EFI on my 58, 3100, 235. This is my first experience installing an EFI system so I’m learning as I go.

I did have to get an adapter made to allow the TB to bolt up to the manifold.

After initial start up, the throttle blade had to be adjusted and it was ready to go. I also had to increase the start fuel percentage, which was done using the touch screen programmer.

Throttle response and starting have been improved. I’ve only driven it about 10 miles so far so I don’t have any fuel mileage numbers yet.

It’s been a fun project.

DB, you have an historic name, ever been in the northwest?

Ed

Once.

What did you do for the fuel system?

Removed the in cab tank and put a 15 gallon tank under the bed. I have a Holley in tank fuel pump. Ran steel lines from the tank to the engine compartment and incorporated a 10 micron filter in the pressure line. The tank is vented with a roll over valve.

Added a Fuel Link to get the 73-10 ohm tank sender to work with the fuel gauge. That still needs some fine tuning.

As long as you don’t mind having the tank in the cab, it would be a lot cheaper and easier to use the in cab tank. You could use an external pump and utilize the tank drain for a return.

I am planning to do fuel injection of some kind on my 58 too. I was looking at doing an underbody tank to get some space in the cab and move the noise of the pump out.

Do you have pics of your filler setup?

Fibonachu,

I wanted to keep the filler out of the box and I couldn’t find a place on the outside of the Fleetside box side that would work so I decided on utilizing the original filler location.

I bought fuel compatible hoses, one with 1” ID and the other 3/4” ID. That matches the fill and filler vent necks on the tank. I also bought a 76 Jeep filler and cap assembly, which fit nicely in the OEM style filler, rubber gasket. I ran the hoses thru the floor, along the outside of the frame rail and clamped them to bed cross sills. I neglected to get any pictures of the hose runs.

You are my hero. The original filler plumbed to the tank is exactly what I wanted to try and figure out how to set up.

Is the filler neck on the top or the side of that tank?

Here’s a better picture of the tank. The upper neck is for the vent, the lower neck is the fill.

What vendor did you get the fuel injection from and who made
Your adapter for the intake??
Very cool set up

I purchased the Holley Sniper, 550-552 from Summit Racing Equipment.

My no-brother-good in-law, who is an excellent fabricator made the adapter. He took a piece of 1 5/8” 4130 tubing and turned the ends down to 1 1/2” and then TIG welded 1 1/2” exhaust pipe flanges onto the turned down ends. I can get you the vendor and P/N of the exhaust flanges if your interested.

Thank you for the compliment.

Put a few more miles on the truck today. Starting and throttle response have made the project worthwhile for me.

Dan,
Love the (My no-brother-good in-law,) comment! That’s funny!
Nice work, by both of you! Keep us informed on the operation and performance!
Jim

Thanks Jim.

I’ll post how it goes once I get some miles on it.

I’m hoping for improved fuel economy, I may be dreaming though.

Don't be surprised if that adapter ends up getting a thick coating of ice if you're in humid conditions. I'd suggest fabricating a square heat box from sheet metal that duplicates the shape of the top of the intake manifold. The fuel evaporating below the throttle plates will drop the temperature pretty dramatically. A friend who ran a liquid Propane injection system many years ago ended up with a 2" thick block of ice around his throttle body after a 25 mile drive, and that was in central California with very low humidity. It jammed his gas pedal linkage at about half throttle.
Jerry

We used to put the Ford 1100 1bbl onto 235 intakes to get rid of the Rottenchester. If this collapsing brain recalls correctly the carb was turned just enough to drill and tap new mount holes. If not the factory holes could be plugged and new holes MILLED into the intake and then tapped. The efi gasket would be installed and a Dremel tool used to blend intake hole to size which would solve the icing problem. All this is emerging from the fuzzy past so use as a suggestion only. Last stovebolt six that left the shop has to have been at least ten years ago and I don't know what I ate yesterday. Now if you're talking LS--pull up a chair.

Jerry,

Thanks for the heads up on the icing. I have noticed the little bit I’ve driven it so far, that the adapter does sweat and is cold to the touch.

When you say ice builds up, is that externally on the adapter? Or will ice form internally and fowl the throttle plate?

Coilover,

That’s some great info on the carb installs and probably still applies here.

My goal when starting this project was to be able to return the carburetor and fuel system back to the original configuration should the EFI not pan out. Wasn’t interested in modifying the intake but it sounds like I may have to go back to the drawing board due to this icing issue. I have not experienced icing yet.

Thanks for the feedback.

For a single barrel carburetor, the stock 235 intake design is about as good as you can get for normal operation on an unmodified engine.
The intake is heated underneath by passages from the exhaust manifold. There is an isolator that goes between the intake and the carburetor base.
I would try to use as much of the original intake, as designed, as possible.

I think Jerry gave you an excellent recommendation in a previous posting (relocating the studs):
https://www.stovebolt.com/ubbthreads/ubbthreads.php/topics/1374608/2.html

I copied the attached intake picture but I failed to note the owner. The top of the intake was cut to study the possibility of adding a 2GC.
Note the heat passages and the cast iron material around it.

The top of the intake manifold must be flat. The isolator sits on top with no gasket. You want perfection here so there are no air leaks (will drive the EFI and carburetor nuts).
There is a gasket between the isolator and carburetor so I assume one would be needed for the EFI.

Bouymaker,

Yes, Jerry did give that guidance awhile back and it’s similar to Coilover’s advice. I appreciate both of them weighing in on this.

While planning this project and searching for an adapter I found two barrel carb adapters but no one barrel adapters. Several vendors sell two barrel carb adapters, none have heat provisions. My guess is some of our fellow Stovebolters are running these two barrel carb adapters and I would appreciate their feedback with regard to icing.

I do not have the carb to manifold isolator installed now.

My heat riser is functional and I have observed it operating.

I have not experienced icing yet, although I have not had a long stretch of operating at cruise power. I need to get that accomplished.

I have observed moisture on the adapter and it is cool to the touch.

My plan is to continue on in the present configuration and see what happens. Am I risking anything other then having to pull over and let the ice melt off?

I will report back with any icing issues that occur.

I drove the truck 10 miles yesterday. It was 68 with 82% humidity and it ran great!

Thank you for your feedback.

First of all, let me just say that I think your install looks great. Truth be told, now that I have seen your set up, I don't know that I would build a stock 235 and use a carb. I will watch your updates eagerly and await your overall assesssment.

I love my multiple carbs, I really do. If I could figure out how to install a pair of 2300 style injectors on my clifford dual intake, I would be doing it right now. But even Holley cant sort out a way for me to run a pair. I would even be willing to go back to a pair of those single bbl style injectors but again Holley has no idea of how to make that work.

But I think that injection will be the future for the old car hobby, taking into consideration the terrible fuel we have available to us, the dwindling number of real carb rebuilders, cores and parts.

Congratulations on your set up!

D B -

What kind of distributor are your running with this? Are you required to run something there compatible with the timing control? Or can it run as fuel-control only?

Dragsix,

Thank you for the compliment.

I agree that fuel injection is going to enable our older vehicles to live on.

The technology exist at a somewhat reasonable price and I feel that in my case it’s a better solution then chasing down a fix for my problematic Rochester B. I’ll freely admit my knowledge of carburetors is limited at best, especially 60 plus year old units. Not an expert on EFI either but I’m learning.

Thanks again!

JW51,

I’m running a Langdon's Mini HEI.

You are not required to run timing control. That’s the way I’m running mine, fuel control only.

The ECU only requires a signal from the negative terminal of your coil for fuel pump control. If the engine stops running with the key on, say due to an accident, the ECU will disable the electric fuel pump.

If you go on Speedways website and look up the Sniper EFI 550-552 and page down a bit, you can print out the QUICKSTART MANUAL and the INSTALLATION MANUAL. Both excellent manuals with easy to follow instructions.

Hope this helps.

Slightly related thought:

There are a lot of GM sixes still on the road. You’d have to assume Holley is working on a bolt on solution for them.

JW51, I also was wondering why Holley first went with TOC (the other companies) and not GM.
I figure TOC engines had to suffer the Autolite 1100 and the Holley 1904 or other model (non glass bowl warping - gas leaking).
Fertile ground for carburetor replacement.
GM had the Carter and Rochester (allowing Carter replacement of the Rochester) and Zenith.
So, I'm obviously biased in my statement, but I'm happy with my Carter YF. No headaches.

I like my YF as well, and no plans to change. But I’d like to be piddling with old rigs for another 40 years, so im also curious how these new-fangled aftermarket EFIs work. I might have no choice but to install one someday.

My main objection to the aftermarket systems is this: Where the heck do I buy parts when I need to get home? A GM HEI is as common as dirt and parts in stock at every store. Same is true of a Holley or Edelbrock carb.

I suspect in 10 years or so, this stuff may be mainstream enough to be in stock at your local FLAPS and my objections will be nullified.

Has anyone used teh FI Tech fuel system? Engine I am going to buy has the Sniper installed but no fuel system. It has a small tank that is fed by your manual pump and then bumps the pressure to the FI unit.

I might ask if I can buy it without the FI and go Fuel Tech. Lots of pros and cons with both set ups,

Technology next to engine heat, poor ventilation, high voltage ignition and gasoline.
The environment for an EFI, in an AD truck, is terrible.

It's rare to create a new tech product that doesn't have bugs initially. Then it takes revisions (product updates) to get it right.
A company like GM with research, R&D and money to make a product that works well and lasts a long time is hard to beat.
This is where smaller companies are at a disadvantage.
I'm in no hurry. My Carter YF and stock ignition works well.
There is no need for me to jump on the EFI bandwagon until a clear winner is known. Maybe in 10 years.

I look for comments posted at the Better Business Bureau and search the Internet for "Product Name" problems.
FI Tech is one of those listed at BBB.

I know several people who used the FiTech Fuel Commander (which is what I think you are talking about) and had no end of problems with them. The concept is fine, but the implementation is pretty bad.

I would keep the sniper and hook up a proper high-pressure system for it. I had the previous version on my vette for about 10 years with zero problems. I only got rid of it because I upgraded to an LS. I know Coilover has good things to say about the FiTech, but the people I know that tried them all ended up switching them out for something else (Snipers, Pro-Flows, or back to carbs).

I intend to either get a sniper or just jump straight to the LS for this build.

I tried FITech on my bolt, and every aspect of it was a bad experience. My solution was an LS swap.

I’ve put 180 miles on the truck since the Sniper install.

No issues yet, other then a finicky cold start now and then. I’ve been adjusting the Fuel Prime table to alleviate this but haven’t hit the correct percentage. Hot starts are effortless.

Here’s some history on the 1958, 235 in my truck. It was completely O/H 9100 miles ago. It was bored .030 over, had hydraulic lifters/cam installed, a full flow oil system and hardened exhaust valve seats installed.

I also have 3.38 gears in the rear.

Below is a picture of the Sniper display while traveling at 60 MPH on a flat stretch of road. The Target AFR is the default setting and is adjustable. Any suggestions on what would be a better Target AFR for the 235?

I haven’t checked the mileage yet but it’s next on the list to be accomplished.

Dan out of curiosity, you are running "fuel control only" mode. What signals does the ECU need in order to fire the injector(s)? Ignition keyswitch ON and RPM signal?
Are these inputs shown on the display? I would expect cold start and hot start to be similar.

What transmission are you running?

Bouymaker,

You are correct. Key on, display and system powers up and fuel pump builds pressure for about 4 seconds. The display does show the cranking RPM once the starter is engaged. The engine cranks normally.

I’m with you, I would think the cold and hot starts would be pretty similar. The system allows you to adjust the percentage of Fuel Prime between 100% and 200%. Fuel Prime occurs as the fuel pump is building pressure after the key is on. It won’t prime again until the engine starts. The default setting is 100%, I’ve got it selected to 120% now but it may need a bit more.

I’ve searched Holley’s website but haven’t found an answer yet. I need to search there some more as I’m sure someone else has had the same issue.

JW51,

I have the three speed transmission, not sure of the model number.

For what it is worth on a slightly different system (Holley Projection) on a 350, I had to set the pre-fueling to about 150%.

That is the equivalent of the "squirt" that you get from pumping the gas pedal before a cold start. The goal is to pre-wet the intake walls and get some aerosol fuel into the intake before cranking it. I suspect that the long (and mismatched) runners on the 235 intake will require a similar value.

Fibonachu,

From your past experience with Holley products, is it realistic to expect the engine to start cold as easily as it does warm? I may be expecting to much.

I’m up to 123% this morning and it started better but probably needs more. Sneaking up on it.

Thanks for the feedback!

It took me a while to get the one I had dialed in, but once it was set I didn't have to touch it for years. I traded it to a buddy who put it on his boat and he is still running it.

I have my 250 setup to run about 16.5:1 air to fuel ratio at highway speeds. I run dual W-1 carters with a standalone A/F gauge. Idle is around 15:1, full throttle 13:1, on flat ground with wind at my back, it will run 17:1, Fuel mileage varies between 20 and 21 mpg @ 65 mph, 3.08 gear 28" tall tires, no overdrive. A/F ratio's will vary at different fuel stations and weather conditions.

Anyone do plug checks in combination with their A/F readings?

Reason for asking….I’d assume the “average” AF reading contains some pretty fair cylinder to cylinder variation the way a GM inline is set up.

Not throwing rocks at the concept, I’m just genuinely curious.